Gajananvk May be organization policies have changed but, this happened all of sudden in a night, from there onwards none of banking app is working.
It is perfectly possible that something in GrapheneOS changed. It is also possible that the banking apps "not working" and the Teams error message correlated in time, but may not share a common cause. I'd still advise you to ask your IT team if something changed. It is, for instance, possible that any changes in policy they made during daytime only came into effect starting at night; perhaps there is a delay between the admin pressing buttons that change policies and the policies actually taking effect. Or perhaps the Teams app or Company Portal only checks your device against policies at certain time intervals, or after certain user actions are performed.
Did you also try reinstalling the Company Portal app? In case this is just some glitch.
Is it possible for you to elaborate on what is not working with the banking apps? Such as, do they display any error messages?